llvm/lib/IR/FunctionInfo.cpp
Teresa Johnson b97baa5fe5 Support for function summary index bitcode sections and files.
Summary:
The bitcode format is described in this document:
  https://drive.google.com/file/d/0B036uwnWM6RWdnBLakxmeDdOeXc/view
For more info on ThinLTO see:
  https://sites.google.com/site/llvmthinlto

The first customer is ThinLTO, however the data structures are designed
and named more generally based on prior feedback. There are a few
comments regarding how certain interfaces are used by ThinLTO, and the
options added here to gold currently have ThinLTO-specific names as the
behavior they provoke is currently ThinLTO-specific.

This patch includes support for generating per-module function indexes,
the combined index file via the gold plugin, and several tests
(more are included with the associated clang patch D11908).

Reviewers: dexonsmith, davidxl, joker.eph

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13107

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249270 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-04 14:33:43 +00:00

64 lines
2.5 KiB
C++

//===-- FunctionInfo.cpp - Function Info Index ----------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the function info index and summary classes for the
// IR library.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/FunctionInfo.h"
#include "llvm/ADT/StringMap.h"
using namespace llvm;
// Create the combined function index/summary from multiple
// per-module instances.
void FunctionInfoIndex::mergeFrom(std::unique_ptr<FunctionInfoIndex> Other,
uint64_t NextModuleId) {
StringRef ModPath;
for (auto &OtherFuncInfoLists : *Other) {
StringRef FuncName = OtherFuncInfoLists.getKey();
FunctionInfoList &List = OtherFuncInfoLists.second;
// Assert that the func info list only has one entry, since we shouldn't
// have duplicate names within a single per-module index.
assert(List.size() == 1);
std::unique_ptr<FunctionInfo> Info = std::move(List.front());
// Add the module path string ref for this module if we haven't already
// saved a reference to it.
if (ModPath.empty())
ModPath =
addModulePath(Info->functionSummary()->modulePath(), NextModuleId);
else
assert(ModPath == Info->functionSummary()->modulePath() &&
"Each module in the combined map should have a unique ID");
// Note the module path string ref was copied above and is still owned by
// the original per-module index. Reset it to the new module path
// string reference owned by the combined index.
Info->functionSummary()->setModulePath(ModPath);
// If it is a local function, rename it.
if (Info->functionSummary()->isLocalFunction()) {
// Any local functions are virtually renamed when being added to the
// combined index map, to disambiguate from other functions with
// the same name. The symbol table created for the combined index
// file should contain the renamed symbols.
FuncName =
FunctionInfoIndex::getGlobalNameForLocal(FuncName, NextModuleId);
}
// Add new function info to existing list. There may be duplicates when
// combining FunctionMap entries, due to COMDAT functions. Any local
// functions were virtually renamed above.
addFunctionInfo(FuncName, std::move(Info));
}
}